Electrical governing apparatus



Aug., i9 1934, 1,505,853 f K. BRAHNARD ELECTRICAL GOVEHNING APPARATUSFiled oct. 9. i920 mim@ Poema Aug. 19, 1924.

UNITED STATES PATENT oFFlcE,

FRANK K. BBAINARD, Ol' WEST ALLIS, WISCONSIN, ASSIGNOR TO ALMS-CHALIEBSMANUFACTURING COMPANY, OF MILWAUKEE, WISCONSIN, A CORPORATION FDELAWARE.

ELECTRICAL GOVERNING APPARATUS.

Application led October 9, 1920. Serial No. 415,931.

To all whom t may concern.

Be it known that FRANK K. BRAINARD, a 4citizen of the United States ofAmerica, residing at West Allis, in the county oi Mil- 5 waukee andState or' Wisconsin, has invented a certain new and useful improvementin Electrica-l Governing Apparatus, of which the following is aspecification. 1 This invention relates in general to reguio lating orgoverning apparatus, and it has .particular relation to apparatus forcontrolfling or regulating prime movers driving electrical apparatus.Regulating or governing apparatus malri ing use oit variations in'frequency of alt/ernating current has been in existence lor some time,the broad principle or operation being that, as the speed ci thegenerator' varies, due to variation in electrical load or otherwise,there is'a corresponding variation in ljlreouency orn the alternatingcurrent generated, this latter variation being utilized to actuatecontrol mechanism or any desired character for regulating the generatoror the supply of motive duid to theA prime mover driving the generator.p Where the control is exercised through vvariations' in frequency whichare responsive to variations in the load on a generator, or it isdesired to'maintain the speed oil the generator substantially constantin spite ci variations in load or pressure at the inlet ot the primemover, there is ordinarily a time element involved in the control, forthe change in speed occurs subsequent to a change in the load or inletpressure. rlhe gene-ral features of the invention include the provisionof means edective to reduce to a ininimum the time 0interval between theocc'lurrence of a load variation and the conse- `uent speed controllingaction exercised ghrough a regulator; in other words to provideelectrically-actuated controlling means which has an action. analogousto that of a mechanical inertia governor.

lt is an object of this invention to rovide an improved type ofregulating devlce embodying electrlcal apparatusresponsive to variationsin acharacteristic of electrical energy. It is a further object of thisinvention to provide an improved type of regulator for prime moversembodying electrical apparatus responsive to the frequency ofalternating current supplied by 'a generator driven through the primemover.

rihese and other objects and advantages are attained by this invention,various novel features of which will appear from the description anddrawing, disclosing one embodiment of such invention, and will be moreparticularly pointed out in the claims.

The drawing is a diagrammatic illustration or apparatus embodyingfeatures of this invention, the same being applied to the control of ahydraulic turbine driving an alternating current generator.

As shown in the drawing, the inlet 9 or a hydraulic turbine l()iscontrolled by suitable means, indicated here by a conventional showingof a valve ll mounted to control the passage ot duid through the inlet9. in alternating current generator l2 is mechant cally connected to thehydraulic turbine l0 to be driven thereby, the slip rings 13 of thegenerator being shown connected to ply line ld, l5, lli.

An improved regulator for controlling the operation of the turbine l0,primarily for the purpose of securing operation thereof at substantiallyconstant speed independently of variations in load on the generator orpressure oii tluid at the turbine inlet, includes `afrequency-responsive relay, indicated generally by R. This relayincludes two opposed electromagnets 2l and 23, preferably or" theplunger type, the plunger-s being designated 2liand 25, respectively,and

the windings therefor being designated 26:

and 27, respectively. These windings are supplied with energy inparallel from one phase of the polyphase transformer 28, thistransformer being connected to the supply line le, 15,16. rlhe winding26 has included in series in its circuit a non-inductive resistance 3land the winding 27 has in series in its circuit an inductance 32, thegeneral purpose of the resist-ance 81 and inductance 32 being to varythe current in the two windings 24 and 25 in response to variations inthe frequency of the current with which these windings are supplied.

a sup- `are such as to permit any desired adjustment, being here shownin the form of threaded members adjustable in fixed supports. c

The ampere-turns of windings 26 and 27 and the resistance '31 andinductance 32 are so selected that under conditionsyof operation of thegenerator 12 at its normal and desired speed, there is a balanced pullon the member 34 through the plungers 24 and.

25, the effect being to maintain the member being completed through theswitch contact 36 and the connector 58 to the other side of the supplyline 49, 50. The connector 58 .may be connected directly to the contact36, as shown, or through the member 34, in/ such case bein preferablyattached thereto at its pivota point.

With the constructive arrangement ldescribed, it will be apparent thaton the completion of the circuit of 'either of the electromagnetwindings 52 and 53, the

plunger or core 51 actuates the switch -48 to` one or the other of itsclosed positions, thereby causing completion of the circuit of the motor46 and consequent closing or opening operation of the inlet valve '11,power. being supplied from the motor 46 throu h the gearing connection45, 43, shaft- 42 and operating mechanism 41. This closing or opening ofthe inlet valve or controller 1l of the prime mover 10 insures thesupply thereto of the required amount of mechanical energy to maintainthe required speed and frequency of the generator 34 and its attachedcontact 36 in linterme- 12 dia-te position with the olatter contact outof engagement with both of the relatively fixed contacts 37 and 38. v V

If desired, one or more damping devices may be used for retarding` themotion of the member 34 to eliminate inconsequential vibrations. Thisdamping device may be in the form of a piston 39 attached to the -member34 and relatively freely movable in fluid contained in a stationarycylinder 40.

The valve 11, or other movable regulator at the inlet of the prime mover10 is actuable by a suitable mechanical connection, designated as 41,and here shown in the form of a sectional gear operated by a worm on ashaft 42 which is connected through reduction gearing 43,45 to the shaftof an electric motor 46. This motor may be of any suitable type, beinghere shown as having its armature vcircuit ,47 connected, through areversing switch 48, to a supply line 49, 50 which may be direct currentor single-phase alternating current. The switch 48 is biased toopen-circuit position and is operable to eitherof its closed positionsby an' electromagnetic device com- 'prising a core 51 and windings 52and 53 effective, when energized, to Idraw the core in oppositedirections to thereby shift the switch 48 -to either of its closedpositions. Springs 54 and 56 are shown for biasing both the switch 48and core 5l to neutral position. One terminal of each of the windings52, 53A connected through the connector-57 to one side of the supplyline 49, 50. The other terminal of. each of the windings 52,53 isconnected to one or the other of the xed contacts 37, 38, the circuitthrough these contacts and the windings With the apparatus shown, itwill be apparent that, on decrease in speed of the prime 'mover 10 andthe generator 12, the electromagnet 23 becomes effective to overpowerthe electromagnet 21, because of the decrease in frequency of thecurrent supplied to the latter, and complete the circuit of the winding53, thus causing closure of the switch 48 and operation of the motor 46in a direction tocause opening of the inlet valve 11, with theconsequent return to normal of the generator 12, on the occurrence ofwhich the electromagnets 21 and 23 again balance each other and hold thecontact 36 out of engagement with the fixed contacts 37 and 38. On theother hand, on increase in speed above normal, the increased frequencyis effective to cut down the current in the winding 27 and permit theelectromagnet 21 to overpower the electromagnet 23, thus causingcompletion of the circuit of the energizing winding of the magnet 52.This causes closure of the switch 48 and operation of the moto-r 46Ain adirection to ycause closure of the controlling element 11, thus reducingthe speed of the prime mover 10 and generator 12 to normal value. Atthis time, the electromagnets 21 and 23 again balance each other and thecontact 36 is held out of engagement with the contacts 37 and 38.

An electromagnetic brake 60 is provided for the shaft of the motor 46 tocause operam tion of the latter to be discontinued upon opening of themotor circuit. The brake is biased to brakingl position and is releasedby the electromagnetwhen the motor circuit is completed through theswitch 48.

It will be' apparent that with onl those features of constructiondescribed a ove, a

regulator is provided which is responsive to variations in speed of theprime mover, acting through the variations in the frequency of thegenerator current, and this regulation is effective to produce desirablecontrol of the prime mover and its generator However,- in order to gainrapidity and refinement in the actuation of the relay R ior speedcontrol purposes, an additional torque-producing e ement is provided foractuating the movable switch contact 36. The arm 34 has attached theretoa ine wire or potential coil 65, this coil being maintained in fixedrelation to the member 34, as b being mounted upon the iframe element67. This potential coil is normally disposed intermediate the coarsewire or series coils 68 and 69, fthe latter being held stationaryrelatively to the movable coil 65, The coils 68 and 69 are connected inseries with each other and in series with one phase o a smallsynchronous motor 7l supplied through the transformer 28, The potentialcoil 65 is connected across one phase ci the circuit supplying thesynchronous motor, The direct current field of the synchronous motor isindicated at 7 2, the same being sup plied from a constant potential`source 73, as shown, or from the direct current supply line 47. Thissynchronous motor is coina paratively small but has mounted on its shalta lly wheel 74 of considerable inertia, the general purpose and effectbeing to maintain the speed of the motor substantially constant 'f inspite of variations in characteristics oil the current supplied theretoAt least, lluetuations in speed of the motor willloe inconsiderablecompared to fluctuations in the current supplied to the motor, this eectbeing secured through the ily-wheel 7l, which has the function oftending to main= tain the speed constant, supplying energy to the motoron any slight decrease in frequency of current, and acting as a load onthe motor to be speeded up thereby on any increase in frequency of thecurrent in the motor circuit, It will be apparent that, on decrease inspeed of the prime mover l0 and generator 12 and consequent decrease inrecppency of the current supplied by the latter, t e current in thecircuit of themotor1 7l decreases, due to the fact that the Hy-wheel 7lgives up some of its energy to the motor and the electrical powerrequired by the latter is decreased, and this decrease in current,acting through the coils 68, 69, destroys the normal balance between thewatt-meter elements consisting of the series coils 68, 69 and thepotential coil 65, the effect being to cause or-assist actuation of themovable element 34 and the contact 36 into engagement with contact 38,the result of which is closing or the switch 48 and the operation of themotor 46 in a direction to cause opening of the controlling valve orthrottle 11. The increased supply of energy to the prime mover bringsthe speed and frequency back to normal.

On the other hand, in case of an increase in speed of the prime mover 10andfgenera- `tor 12, such as might occur upon the removal of electricalload therefrom, and the consequent increase or" the current in thesupply line, the inotor 47l tends to speed up, being opposed by theily-wheel 74 acting as a load 4on the motor, the general result beingthat winding 52, and consequent closure of the switch i8 and operationof the motor i6 in a direction to cause closing ci the inlet valve orthrottle ll. The decreased supply ci energy brings the speed and`lrequeiicy bach to normal.

The distinctive feature oi:a operation oil the watt-meter element oi therelay consisting ofthe potential coil 65 and the current coils 68, 69supplied through the circuit ol the synchronous motor 7l, is that thereis no appreciable element oi time involved in its e aective operation.lt may be said that effective operation of the relay through the coils65, 68, 69 may occur at the commencement oit a change in generator speedand frequency, for a very small variation in speed or requency can causesuilicient variation in the current supplied to the wat meter device tocause the desired operation oic the contact 36. llt may be consideredthat the regulator with the ily-wheel synchronous motor has an actionanalogous to that of a` mechanical inertia governor rather than anordinary speed governor, the regulator itunetioning upon a tendency toappreciable lchange in frequency rather than awaiting the actualoccurrence oi'i'appreciable-chan l"e, such as might otherwise beoccasioned oy variation in, load upon the generator. Accordingly, it maybe pro er to refer to the regulator as an electrical y-operatedl inertiagovernor., y

ln line with this consideration, in the case of the particular type ofmotor disclosed herein, it may be considered that the controllingeli'ect is due to the change in displacement of the field of the motorrelatively to the pole centers oit the armature.

lt will be apparent that the amount ol power available ior operation ofthe wattmeter device is inherently dependent upon the rate of change inthe frequency ci the energy supplied to the motor; and this 'rate timeelement in the operation of devices for` vquency; while the torqueexerted by the electromagnets 2l and 23 is responsive to the attainmentof some definite `value of frequency above or below the normal value.

It will be apparent that the improved regulating device described hereinis capable of securing not only the control exercised through. theordinary .frequency-responsive regulator, but also an improvedandretined control exercised through the watt-meter element, this lattercontrol being more rapid and more nearly in synchronism with the actualload or other change on the.. generator.

In its broader aspects, the invention is not necessarily limited tofrequency responsive or frequency controlling devices. rlhe ilywheel.motor may be one which has a tendency to change its speed in response tothe voltage impressed thereon, generally for the purpose vof checkingsubstantial variation in the voltage or other characteristic of thegenerator. Likewise, while a synchronous motor is specifically describedas the means for controlling the watt-meter device, it will be apparentthat this motor may be of the induction or other type wherein acharacteristic ot the energy or current supplied to the motor isvariable, through the eect of the fly-wheel.

It will be apparent' that a single controlling apparatus of thecharacter described herein maybe utilized to control simultaneously aplurality ofprime movers driving several generators connected in.parallel to the same supply circuit.

rlhe prime mover or the inlet controlling means therefor may be of anyordinary and l well known character such as adjustment of theguide-varies or-inlet nozzle of a hydraulicturbine, or adjustment of thethrottle of a steam engine or turbine. A

It should be understood that the invention claimed is not limited to theexact details of construction shown and described herein, for obviousmodifications will occur to one skilled in the art.

It is claimed and desired to secure by Letters Patent:

1. A governing apparatus comprising an electric motor tending tomaintain its speed substantially constant in spite of variations in acharacteristic of: the -current supplied to the motor, a deviceresponsive to variations-from normal in the electrical power to maintainthe speed of the motor substan- A,

tially constant in spite of variations in the frequency of the currentsupplied to the motoryand a controlling element responsive to variationsfrom normal in a characteristic of the electrical energy supplied tosaid motor. 3. A govermng apparatus comprising an alternatin currentmotor whom speed tends to respon to the'frequency of the currentsupplied thereto and having a rotating element of considerableinertiajending to maintain the speed of the motor substantially constant1n spite of variations in frequency of the current supplied to themotor, a device responsive to variations from normal in the electricalpower supplied to said motor, and a controlling element actuatable bysaid device.

4. A governing apparatus comprising a synchronous motor having meanstending to maintain its speed' substantially constant in spite ofvariations in frequency of the current supplied to the motor, a deviceresponsive to variations from normal in a characteristic of theelectrical power supplied to4 said motor, and a controlling elementactuatable by said device.

A 5. ,A governing apparatus comprising an alternating current motorwhose speed tends to vary in response to the frequency of the currentsupplied to the motor and having a rotating element ofconsid'erableinertia tending to maintain the speed of the motor substantiallyconstant in spite of variations in frequency of the current supplied tothe motor, a torque-producing device responsive to variations rornnormalin a characteristic of the power supplied to said motor, anelectromagnetic device responsive to varia.- tions in the frequency ofthe current supplied to said motor, and a controlling element actuatablein response to effects prolll duced thereon by eithersaid'torque-producing device or said electromagnetic device.A

6. A governing apparatus comprising a synchronous motor having airotating element of considerable inertia tending to maintain the speedof the motor substantially constant 1nl spite of variations in frequencyof the current supplied to the motor,

from normal in the electrical power supplied to said motor, anelectromagnetic device inoperative under conditions of normal frequencyand responsive to abnormal frequency of current inthe circuit supplyingsaid motor, and a controlling element actu- "a watt-meter deviceresponsive to variations l y f 1,505,853

` atable in response to effects produced there- 'onjby either saidfrequency-responsiyve device or said Watt-meter device.

` 7. A governing apparatus comprising an alternatln current motor whosespeed tends to respon to the frequency of the current supplied theretoand having a rotating element'A of 'considerable inertia tending tomaintain the speed of the motor substantially constant in spite orvariations in frequency of the current' supplied to the motor, awatt-meter device having a potential coil and a series coil carryin'current proportional to the current in t e circuit of said motor, anelectromagnetic device operative in response to conditions of abnormalfrequency of the current supplied to said motor, a controlling elementactuatable in response to eii'ects produced thereon by either saidfrequency-responsive device or said wattmeter device..v v

8. .d governing apparatus ,comprising a synchronous motor having arotating elenient oiZ considerable inertia tending to maintain the speedof the motor substantially Constantin spite of variations in frequencyoi' the current supplied to the motor, a watt-meter device having apotential coil and a series coil carrying current proportional to thecurrent in the circuit of said motor, an electromagnetic deviceresponsive 4to conditions oi abnormal frequency of currentv in thecircuit supplying said motor, and a double-acting contact deviceactuatable by either said frequency-responsive device `or saidwatt-meter device 9. ln combination with a primelmover, a generatordriven thereby, means for controlling the supply or' energy to saidplrune mover, a motor suppliedwith energy trom said generator andtending to maintain its speed substantiallyconstant in spite oivariations in a characteristicothe electrical power supplied thereto, adevice responsive to variations from normal in the electricall sive tovariations from normal in the electrical power supplied to said motor,and a controlling element actuated by said device and operative toadjust said energy-controlling means for said prime mover.

11. In combination with a prime mover, a

j vice inoperative under conditions of normal generator mechanicallyconnected in driven relation to said prime mover, means for controllingthe supply of energy to said prime mover, an alternating current motorsupplied with energy from said generator and whose speed tends to resond to a characteristie of the powersupplled th/ereto and having arotating element of considerable inertia tending to maintain the speedoi' the, motorsubstantially constant in spite of variations in acharacteristic of the electrical energy supplied thereto, a watt-meterdevice having a potential coil and a series coil carrying currentproportional to the current in the circuit ci said motor, anelectromagnetic device responsive to abnormal frequency of the currentsupplied to said motor, a controlling element actuatable in response toeects produced thereon by either said reogxuency-responsive device orsaid watt-meter device and operative to adjust said energycontrollingmeans :tor said prime rnovenl 12. ln combination with a prime mover, agenerator mechanically connected in driven j relation thereto, asynchronous motor supplied with, energy from said generator and having arotating element of considerable in-- ertia tending to maintain thespeed oif the motor substantially constant in spite ot variations infrequency oi the current supplied to the motor, a Watt-meter devicehaving a potential coil and a series coil carrying current proportionalto the current in the circuit or said motor, an electromagnetic del0@requency and responsiveto abnormal frequency of current in the circuitsupplying said motor, a double-acting Contact device actuatable inresponse ,to eects produced thereon -by either said frequency-responsivedevice` or said watt-meter device and operative to adjust saidenergy-controlling means for said'prime mover.

13, A; governing apparatus comprising a power responsive device, afrequency responsive device for controlling the power supplied to saidpower responsive device, and a controlling element actuatable throughsaid power responsive device. j

14. lfgoverning apparatus comprising a power responsive device, a deviceresponsive to the rate oi change of frequency for controlling said powerresponsive'devicdand a controlling element actuatable through said powerresponsive device.,

l5. A governing apparatus comprising a device operatively responsive toboth increase and decrease of a characteristic oi the energy in anelectrical circuit and further responsive to the rate of such increaseand decrease, and a controlling element actuatable through operation ci'said device.

16. A governing apparatus' comprising a device responsive to the rate ofboth increase and decrease in a characteristic of the lill energy inelectrical circuit, and a controllin element actuatable through saiddevice.

l A governing apparatus comprising a device responsive to a variation from normal of the frequency of the current 1n an electrical circuit, adevice responsive to the rate of change of said frequency, and acontrolling element actuatable by said two devices.

18. A governing apparatus comprislng a device responsive to variationsfrom a norrnal value in a characteristic of the current in an electricalcircuit, a device responsive to the rate of change of saidcharacteristic, and a controlling element .actuatable by said twodevices.-

'19. A governing apparatus comprising an alternating current motorhaving a rotatable element of considerable inertia and adapted to resistchanges in the operating speed thereof in spite of variation in acharacteristic of the current supplied to said motor, a deviceresponsive to the electrical power supplied to said motor, a deviceresponsive to said characteristic of the current, md a? controllingelement actuatable by said two devices.

20. n electrically operated governing apparatus comprising a deviceresponsive to the rate of change of the :frequency of an electricalcircuit to a degree directly proportional tosuch rateof change, and acontrolling element actuatable through said device.

21. ln combination with an electrical circuit and an electricalgenerator for supplying said circuit, apparatus for controlling saidcircuit, comprising a device responsive to a variation from normal of acharacteristic of the energy of said circuit, means directly responsiveto the rate of change of a characteristic of said energy for alteringthe operating eectlof said device, and a controllin element actuatableby said device.

22. governing apparatus for controlling an alternating currentelectrical circuit, comprising a controlling circuit, anelectromagnetically actuated device operatively rensoaeas sponsive tothe frequency of said electrical circuit, and electromagnetically1actuated meansresponsive to the current 1n said controllin circuit forcausing the responsiveness o? rate of change of the frequency in saidelectrical circuit.

23. A governing apparatus comprising an alternating current motor thespeed of whose rotating element tends to respond tov the frequency ofthe current supplied thereto, and having means tending to maintain thespeed of said rotating element substantially constant in spite ofvariations from normal value in the frequency of the current said deviceto vary directly as the supplied to the motor, anda controlling elementresponsive, through effects due to said motor, to variations from normalin the frequency of the electrical energy supplied to said motor.

24.. A governing apparatus comprisin a synchronous motor having meanstending.

element thereof substantially constant in I spite of variations in acharacteristic of the electrical power supplied thereto, and meansoperative to adjust said energy controlling means for said prime mover,said adjustix` means being responsive to effects produc through saidmotor on variation from normal value of the speed of said prime mover.ln testimony whereof, the signature of the inventor is aiixed hereto.

FRANK K. BRAINARD.

